Hollow masonry building unit



YV. A.. BARNHART HOLLOW MASONRY BUILDING UNT Dec. 1, 1953 2 sheets-sheet 1 Filed Sept. 11, 1946 f ,i 24a',

INVENTOR VERN A. BARNHART ATTORNEY Dec. 1, 1953 v. A. BARNHART HOLLOW MASONRY BUILDING UNIT Filed Sept. ll, 1946 2 Sheets-Sheet 2 .INVENTOR VERN A. BA RNHART l I f ATTORNEY Patented Dec. 1, 1953 UNITED STATES PATENT OFFICE HOLLOW MASONRY BUILDING UNIT .Vern A. Barnhart, Athens, Ohio Application September 11, 1946, Serial N o. 696,283

7 Claims. L(Cl. 'i2-41) This invention relates to masonry building units, and particularly to those provided with voids which open into the bonding surfaces.

Masonry building units of this type are made in a variety of different forms and of a variety of different materials. An example is the well known hollow structural tile made of clay and red in a kiln. Both the peripheral walls and any partition walls that may be provided are comparatively thin in order to reduce weight and the quantity of material used. The wall surfaces are normally smooth and dense by reason of the manner in which the units are formed, the customary method being extrusion of the plastic clay through a suitable forming die, and cutting olf of the individual unit 'lengths from the extruded column by means of wires.

Considerable difficulty has been experienced in the laying of such hollow structural tile units, because of the narrow and smooth nature of the bonding surfaces. diilculty, and then in limited quantity which is likely to be depleted by the falling oil of portions during the laying process. This is not only aggravating to the Workman, who must apply additional portions of mortar to make up for that thus lost, but is extremelywasteful. The mortar usually falls into the interior of the wall where it cannot be recovered, and the working time |lost by the mason is considerable. Furthermore, the resulting bond is a precarious one. It is thinner than desirable vfor strength and permanency, and is uncertain in its gripping characteristics. Too, due to the density and smoothness of the bonding surfaces-especially in instances of salt-glazed tile and other substantially impervious units-the time for setting of the mortar is inordinately long, thereby further delaying the mason in his Work.

By the present invention I overcome the above difculties in a very simple fashion which adds nothing to the weight of the unit and very little if anything to the cost of production. Prior to the setting or firing of the unit, and preferably during and as a part of the extrusion process, I scratch or plow up the skin surface of part or all of those'interior walls of the unit which border the bonding surfaces. By scratch or plow up I mean the breaking up or roughening of the otherwise smooth and dense skin surface so that innumerable particles andV curls of the material project out beyond whatl would otherwise be the normal tight-skin wall face. These add considerably to the wall thickness of the unit and, thus, to the actual bonding area. They v Mortar adheres only withv also serve to catch and retain mortar exudate from the mortared joints, preventing loss and adding greatly to the size, strength, and permanence of the resulting joinder. Furthermore, because they render certain wall surface with which the mortar comes into intimate contact relatively porous, and thereby produce a suction effect, they speed the drying and setting of the mortar. Again, this roughness of wall surface and relatively greater porosity provide for the absorption of sound and prevent moisture condensation within the unit, thereby enhancing the insulating value of the units to an exceptional degree.

Accordingly, principal objects of the invention are:

(a) To reduce the time and labor necessary in using hollow masonry units in building construction;

(b) To greatly increase the strength and permanence of structures constructed with hollow masonry units;

(c) To lessen the cost of hollow masonry unit building construction;

(d) To substantially increase the insulating value of hollow masonry unit building construction; 1

(e) To provide a hollow masonry building unit having considerably greater bonding area than is customary, without increasing the weight or bulk of the unit and with little or no increase in manufacturing cost; e

(f) To provide a hollow masonry building unit having sufficient porosity adjacent the bonding areas to produce effective suction characteristics, for accelerating the rate of mortar set and mor- (y) To increase the mortar grip, bonding, and setting area of hollow masonry building units;

(h) To provide a, certain water permeability at critical bonding areas of otherwise impervious hollow masonry building units;

(i) To eliminate loose mortar joints in hollow masonry unit building construction;

(i) To provide for a certain amount of breathing of interior wall surfaces of hollow masonry unit building construction to prevent moisture condensation thereat;

(lc) To increase the resistance of hollow masonry unit building construction to heavy impacts;

(l) To make it unnecessary to grind salt-glaze hollow masonry building units at critical bonding areas;

(m) To make practical the wide-spread use of special problem in 3 substantially impervious hollow masonry building units;

(n) To effect substantial savings in the mortar cost of hollow masonry unit building conlegis ad': is'irlrS"vif tf1? invention will be more fully understood from 'the' following detailed description of the preferred y. specic forms thereof illustrated in the accom v ..lngthi'voidgare similar to the surfaces Ib panying drawings, wherein: Fig. 1 represents Fig. 6, a'ifragmen'tary-f perspective viewfpar-f tially-l in section illustrating 'a critical stage-1n the V'producti'n by extrusion of the horizontal unit of Fig.'2;` -v'fi l "Y Fig. 7, an enlarged fragmentary vdetail view'in vertical section of themeans employed in Fig. 6 for breaking or plowing' the otherwise smooth and dense inner wall surfaces of the extruded tile. building unit; y Y' i v Fig.' 8, vafragmentaryperspective viewof'a somewhat different type of masonry building unit infaccordance with the invention; i Y Y '-Flg. 9, a View siniilar 'to 'that of Fig; 5 but showing only one of the masonry' building Iunits', such -unit having 4the scratching land 'roughening of its inner wall faces Yarranged in a s omewhatv differentvfnannerl; I I Fig.' lOya fragmentary view corresp'ondin'gfto that of Fig. 2 but illustrating a unit in whichtlie scratching and"roughening 'o f the innerwall -fa'ces isy arran'g'diinstill va different manner;

a perspective view .ofwa ver.- tical type hollow structural tile building' unitv single partially in vertical 4 scaried, namely, of scratched or plowed-up nature, wherein particles of the surface are loosened and project outwardly beyond the normal surface line.

The vertical type unit l0 has its hollow interior divided by partition walls lila into vertically extending voids I2, and it is the interior walls defining these voidsv that Kare roughened, su In the cseiprthe horizontal type unit n, a void I4 extends completely through the The plowed-up interior surfaces IIb derived-up fsurfacsz beinglindicated 10b?.

unit.

of the vertical type unit of Fig. l.

.eegloughning or plowing-up of these in- .te olxsmgfaqgsugf, units conforming to the inv` Aon is advantageously accomplished during th'f'oifming process. A usual method of forming structural tile units; is to extrude the plastic clay thi-oughtaI suitable :extrusion die, ,cutting off the:A individual units from: thefi continuous. exe' trudatebyf fine, tightly stretched` wires.A Pursuant to the invention and as-a lfeature thereof, ther interior, -voi'd-dening .surfaces of the -units are'r ro'ughenedv during the .extrusion process wthoutcomplicatingthat process or increasing. its cost: kTo .this end,.thecore block of the die is Vprovidedwith' arr. auxiliarysection vspaced therefrom. farther .along the .line y of 'material ow. SuchV an auxiliary.. seotioniisk designated l'imFi'g.. 6, .where-fafxhori'zontal type unitis shown in the process =.of-lbeing..-formed=, the appended arrow indicatingthe direction-of. material flows-.1; Asth'er'eillustrated,- see also Fig. .7, .the- .auxiliary sectiorr l'comprises. a dielolock slightly smalle'rrin peripheryithan themain .die lolnck, and;:scratchingSor-,plowing elements ...t6 inset.....in*losely'fzspaced relationship `about the peripheral surface thereof ,r such. elements t6. ex-

0 .tendingfioutwardl-y.intotheline'of travel of the raising:orwplowingeupfthe surface and'near-sur- Fig. l1', a perspectivejviewfof a cored-form 'of standard building brick to has been applied. l y y Referring now" tothe jdrawings, andv particularlyto Figs. A'l' through '7 thereof: hollow masonry which the invention building units thes'trlictulal tile Varietyare customarily produced in the formof vertical type and horizontal type units, the hea'djoifi't's of the formerI being'disposedhorizontally between adjoining masonry courses-and thoseof the flatter vertically betweenadjoining Vunits within' a course. The horizontal typeis usually spoken of as a side set unit,`an`d presentv'sa the' making of the vertically disposed head joint, -wh'ereiny a'relativ'ely vthin band of wetmortar must bemade to ,stand vertic'ally between the adjoiningk units untill set;l

In. Fig. 3' is illustrated. part of 'a `building co'hstruction made up of vertical type. hollowjtile units. l0, illustrate'dperse. in Fig: l, and in'Fig.

5 's llustrateda partnfasimilarbuilding conably. s illustrated, "'Jth'ewrughenin'g is of ift 'faceparti-cles as thezextrudatetravels by. e f` The .ifi'epth` ofp'enetration of1 the scratching. .or .plowing elements.' andthe .extent of raising-irpef 'surface and subsurface-`particles maybe deter; mined. as seen. tvinthe particular case; Ordi- .narily,.such scratching or -plowingup. will bei ex- -tensive, proj ecting 's particles -fand small curls of i-thematerialfas `fa1-..a"s 531e linchfor more beyond the normalxsnicothskin surface without detachfing :them 'fromthe main body.; vThe average. exftensio'n. ofethe .'suifaceioutwardly. of the main .body of.. material lwill'.approximate- 1/8 of: an inch '.verywffectivelyin ymost instances of practical application.

{Ifhave :foundithat/curving-the. scratching or plowingielementsfxl against the; material flow, asf shownjr'or 'setting'fther'rl atan acute1r angle therea'gainst 1 is decidedly aadvantageous, produc..- `ing. considerably f' greater rnughness .than .if they .project straight 'from' the die blocks at right anfgles to theaplpwsI-.A vn .3: .Considering OW. the

l use. of. hollow masonry unitsv form'edri in accordance with the, invention,

.-,inbuildngcfwith thegvertical units lg, as illus- .tratecl infFig. morta-ril is .applied t0. the relaltively narrpwhprizontal bonding surfaces 8K-in -qsantityfsumcieet-t@ Pro 'id e l l .j nt. er the smooth dense interior wall surfaces, these curls of mortar almost invariably slip and slough off, falling through the voids to the ground. Besides the waste thus caused, the loss of these portions of the mortar seriously weakens the resulting joint. With units formed in accordance with the invention, however, the mortar exudate grips the roughened surfaces bordering the joinder and remains as an integral part of the resulting joint, see the exudate lla, Figs. 3 and 4.

The retention of the mortar exudate lla does more than enhance the strength of the joint; it means that a substantial portion of the wet mortar of the joint is in contact with relatively porous bonding areas of the masonry units, and that the entire body of mortar benefits from the suction characteristics exhibited by these areas. That is to say, the entire mortar joint sets more rapidly and securely.

In building with the horizontal units I I, as illustrated in Fig. 5, vertical head joints 2U must be made to stand up between the narrow end surfaces of the units until the mortar sets. This is exceedingly difficult to accomplish with ordinary units, and a mason must be not only highly skilled but also extremely patient to Work successfully. He must wait for the mortar to partially set before tooling the vertical joints, which means slower work and greater building cost. With units formed in accordance with the invention, however, here specifically the units il, little if any difficulty is experienced by even a relatively unskilled mason. The exudate 20a curling to either side of the joint around the extent thereof is gripped by the projecting particles of the roughened interior wall surfaces Hb and held firmly, enabling tooling of the vertical joints without delay and producing a strong and eiective joinder.

If desired, the invention may be applied to double wall units of the horizontal type, as illustrated by the unit 2 l, Fig. 8, where roughened interior walls 2l b are provided throughout.

In some instances it may be desirable to roughenonly those portions of the interior wall surfaces of the unit which are marginal to the bonding areas thereof. In Fig. 9 is illustrated a horizontal type unit 22 having only the marginal portions 22h adjacent the respective end bonding areas 23 roughened in accordance with the invention.

Again it may be desirable in certain instances to have only the two face or bearing walls roughened interiorly, either in full, or marginally. Thus, in Fig. 10 the horizontal unit 24 has only the interior surfaces of its respective face or bearing walls 24a roughened pursuant to the invention, as indicated at 24o.

Standard shaped bricks of the cored variety, particularly impervious types, may be formed in accordance with the invention to advantage. As illustrated in Fig. 11, where a standard shaped brick 26 provided with the open cores 2l is shown, the interior wall faces of the cores may be roughened in the manner disclosed hereinbefore, forming relatively porous mortar-grip surfaces which aid considerably in the setting of the mortar joints between adjoining bricks.

In all instances the roughened surfaces, to the extent provided, fulfill more than a mortar gripping and retaining function. They prevent or considerably lessen moisture condensation within wall construction, because of the relatively great increase in surface porosity-an increase of twice according to experimental evidence. Further,

- inbefore mentioned.

'Ihe method of roughening as herein-set forth is a decided advantage in the production of the units, Athough the roughening may be effected in a varietyof ways, for example, by a hand tool after the forming but before the burning or hardening of the units. Thus, it will .be seen that although the illustrated furrowing provides an advantageous roughened formation, a variety of other types of roughening treatments within the skill of the art, which break the otherwise skintight surface and project particles of the material therebeyond, may be employed.

Whereas this invention has been described with respect to certain specific forms thereof it should be understood that various other forms may be produced from time to time by those skilled in the art on the basis of the teachings hereof without departing from the generic purview of the invention as defined by the following claims.

I claim:

l, A hollow masonry building unit having at least one interior void which opens at opposite ends into opposite mortar bonding faces of the unit and is otherwise enclosed by walls whose interior surfaces have numerous scarications disrupting them and rendering them rough and porous, said scarications comprising alternate ridges and furrows lying side-by-side along said wall surfaces and extending substantially perpendicularly to and individually intersecting and opening into said opposite mortar bonding faces, so that the excess of mortar applied to said bond.. ing faces and exuding therefrom in the laying of the units will tend to now naturally into and along said furrows and cling to said rough wall surfaces, and excess liquid in said mortar will be absorbed through said porous wall surfaces into the body of the unit.

2. The building unit recited in claim 1, wherein the building unit is a red, extruded clay, structural tile.

3. The building unit recited in claim 2, wherein the structural tile is a side-set horizontal unit having the mortar bonding faces vertically disposed.

4. The building unit recited in claim 1, wherein the building unit is a brick cored to provide said void.

5. A hollow masonry building unit having at least one interior void which opens at opposite ends into opposite, vertically spaced, mortar bonding faces of the unit and is otherwise enclosed by walls whose interior surfaces have numerous scariiications disrupting them and rendering them rough and porous, said scarications comprising alternate ridges and furrows lying side-by-side along said wall surfaces and extending substantially perpendicularly to and individually intersecting and opening into said opposite mortar bonding faces, so that the excess of mortar applied to said bonding faces and exuding therefrom in the laying of the units will tend to flow naturally into and along said furrows and cling to said rough wall surfaces, and excess liquid in said mortar will be absorbed through said porous wall surfaces into the body of the unit.

6. The building unit recited in claim 5, wherein the building unit is a fired, extruded clay, structural tile.

7. The building unit recited in claim 5, wherein 

